Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HSF - Pharmacology > Pharmacokinetics > Flashcards

Pharmacokinetics Flashcards

1
Q

Factors involved in pharmacokinetics

A

Absorption
Distribution
Metabolism
Elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Oral delivery pros

A

Parient-preferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Oral delivery cons

A

Enters portal blood system, subject to first-pass metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Methods of delivery to avoid first-pass metabolism:
1)
2)
3)

A

1) Transdermal (patch, injection)
2) Bottom of rectum, vagina
3) Inhalation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q 
Types of injection
1)
2)
3)
4)
A

1) Intramuscular
2) Subcutaneous
3) Intrathecal
4) Intravenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Intrathecal administration

A

Into subarachnoid space in brain or spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How concentration gradient between villi and lumen is kept high

A

Many blood vessels in villi wash away solutes, keeping concentration gradient high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Ways to cross epithelium
1)
2)
3)

A

1) Paracellular
2) Transcellular
3) Transport across cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Paracellular

A

Between cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Transcellular

A

Through cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Transport across cell

A

Different transporters for different nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Type of molecules most readily absorbed by body

A

LIpid soluble molecules

Greatest surface area across cell membrane is where transcellular and transport across cell occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Example of pH trapping of a drug

A

ASPIRIN

1) In stomach, pH=1, aspirin is uncharged and can’t donate H+
2) In blood, pH=7.4, aspirin is charged and can donate H+
3) Is water soluble at pH=7.4, can’t diffuse out of blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Exception to the capillaries–>venules–>veins norm

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Standard capillaries

A

Pinocytotic vesicles, uninterrupted endothelium, continous basal lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Fenestrated capillaries location

A

Liver, kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Fenestrated capillaries characteristics

A

Small holes in endothelium

Proteinaceous mesh across holes to filter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Tight capillary location

A

Brain. Forms blood-brain barrier

Tight junctions between endothelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why modern antihistamines don’t make you drowsy

A

1st generation were uncharged, could cross into brain

2nd generation charged, can’t cross into brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Mepyramine

A

1st generation antihistamine

H1 antagonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Fexofenadine

A

2nd generation antihistamine

H1 antagonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

1st generation antihistamine

A

Mepyramine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

2nd generation antihistamine

A

Fexofenadine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Normalised blood flor

A

mL/minute/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Thiopental

A

Fast-acting anaesthetic, long half-life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Thiopental concentration peaks

A

1) Brain - 10 minutes
2) Liver
3) Muscle
4) Fat - around 6 hours
5) Slowly reenters blood, broken down in liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Thiopental administration

A

As a rapid bolus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Thyroxin binding-protein

A

Thyroid-hormone binding protein

29
Q

Effect of thyroid-hormone binding protein

A

Increases half-life of thyroxine to around 1 week

30
Q

Reason for drug-binding proteins

A

Proteins too large to be filtered in nephron

Hormone not excreted

31
Q

Is entry through hepatic artery first-pass metabolism?

A

No

32
Q

Aspirin action

A

Inhibits cyclo-oxygenase

33
Q

Cyclo-oxygenase function

A

Catalyses first step in prostaglandin, thromboxane synthesis

34
Q

Catalyst of thromboxane, prostaglandin synthesis

A

Cyclo-oxygenase

35
Q

Aspirin dose for NSAID

A

350mg every 4 hours

36
Q

Aspirin dose for platelet function suppression

A

50mg/day

37
Q

Effect of 50mg aspirin per day

A

Suppresses platelet clotting

38
Q

Rationale behind 50mg aspirin per day

A

Platelets can produce their own COX proteins, can’t replenish inhibited COX

39
Q

Phases of liver metabolism
1)
2)

A

Phase 1) Modify functional groups, mainly by cytochrome P450 (CYP)
Phase 2) Attachment of sugar derivative

40
Q

Reasons for phases of liver metabolism
1)
2)

A

1) Make more charged and water-soluble

2) Make more charged and water soluble

41
Q

Role of cytochrome P450

A

Modify functional groups on drug in liver first-pass metabolism

42
Q

Reason for hepatic first-pass metabolism

A

Make drugs easier for the kidneys to excrete

43
Q 
ORder of blood vessels in nephron:
1)
2)
3)
4)
5)
6)
A

1) Afferent arteriole
2) Glomerulus
3) Efferent arteriole
4) Capillaries
5) Arteriole
6) Capillaries

44
Q

Where filtration occurs in the nephron

A

Glomerular capillary

45
Q

Amount of kidney filtrate per day

A

180L

46
Q

Proportion of blood filtered per pass through the glomerulus

A

15-20%

47
Q

Configuration of glomerular endothelial cells

A

Heavily fenestrated

48
Q

Molecules that get most easily filtered in the glomerulus

A

Small, positively charged

49
Q

Characteristics of proximal tubular cells

A

Have microvilli

Have a high mitochondrial density

50
Q

Pumps that actively pump solutes into filtrate

A

Organic anion transporters and organic cation transporters (OATs, OCTs)

51
Q

How to reduce excretion of a drug
1)
2)

A

1) Protein binding

2) Administer another chemical that will compete for OAT/OCT with drug

52
Q

Example of secreted anions competing for OAT

A

Bile salts and penicillin

Aspirin and probenecid

53
Q

Example of cations competing for OCT

A

Creatine and atropine

Morphine and adrenaline

54
Q

Example of active reabsorption

A

Glucose uptake in proximal tubules

55
Q

Example of passive reabsorption

A

pH-dependent reabsorption of lipid-soluble molecules

56
Q

Difficulty in excreting uncharged molecules

A

Lipid soluble, so cross membrane easily

57
Q

Saturable nephronic processes

A

Secretion and active reabsorption

58
Q

Non-saturable nephronic processes

A

Filtration and passive reabsorption

59
Q

Bioavailability

A

Quantity of drug in circulation divided by quantity of drug administered

60
Q

IV bioavailability

A

100%

61
Q

Volume of distribution

A

Volume that a solute would occupy if the same concentration as it is in the plasma

62
Q

Implication of a high volume of distribution

A

Drug is being stored in tissues rather than plasma

63
Q

Factors affecting volume of distribution

A

Bind to tissue proteins - increase Vd

Bind to plasma proteins - decrease Vd

64
Q

Clearance

A

(Metabolism+excretion)/[DRUGplasma]

65
Q

Units used for clearance

A

L/min

66
Q

Factors influencing clearance:
1)
2)
3)

A

1) Hepatic and renal enzyme expression
2) Competition between drugs for enzymes
3) Hepatic, renal disease

67
Q

Effect of concentration on clearance

A

None (for most drugs)

EXCEPTION: alcohol

68
Q

Half life equation

A

(ln(2)*Vd)/Clearance

69
Q

First-order pharmacokinetics

A

Fixed half life

HSF - Pharmacology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions